Hi,
Forgot the copy the WG on this. Here it is.
Zhe
------------------------------------------------------------------------
Subject:
Re: A proposal for a way forward regarding fragments
From:
Alan Wu <alan.wu@oracle.com>
Date:
Tue, 04 Mar 2008 17:56:09 -0500
To:
Boris Motik <boris.motik@comlab.ox.ac.uk>, bcg@cs.man.ac.uk
To:
Boris Motik <boris.motik@comlab.ox.ac.uk>, bcg@cs.man.ac.uk
CC:
hendler@cs.rpi.edu, 'Jeremy Carroll' <jjc@hpl.hp.com>, 'Michael
Schneider' <schneid@fzi.de>
Dear Boris and Bernardo,
Thanks very much for your hard work. In general, I am very happy to see
those axiomatic rules on top of DLP. They do seem vendor
friendly. A few questions and comments so far,
* the transitivity of rdfs:subClassOf and rdfs:subPropertyOf is not
reflected in the rules. Is that intentional or am I missing something?
I understand that you took out "if" condition from the iff condition
in Section 4.3.1. However, given
T(?c1, rdfs:subClassOf, ?c2) and T(?c2, rdfs:subClassOf, ?c3),
users would naturally expect to see
T(?c1, rdfs:subClassOf, ?c3)
* Along the same line, do we want to generate rdfs:subClassOf (resp.
rdfs:subPropertyOf) based on
owl:equivalentClass (resp. owl:equivalentProperty)? and vice versa?
* If rdfs:subClassOf triples can be generated, then those N rules in
Table 3 regarding rdf:unionOf (should be owl:unionOf)
can be simplified into one rule deducing that T(?C1, rdfs:subClassOf,
?C), T(?C2, rdfs:subClassOf, ?C) ...
T(?Cn, rdfs:subClassOf, ?C)
* Should the T(?x1, rdf:unionOf, ?c) in those N rules in Table 3
regarding rdf:unionOf
be T(?c, rdf:unionOf, ?x1). Ignore the typo for now.
Same thing for T(?x1, rdf:intersectionOf, ?c) in Table 3.
* domain/range rules are missing. I guess we can simply import rules
rdfs2 & rdfs3 from
http://www.w3.org/TR/rdf-mt/
Since you took out if condition, we don't need rules ext1, ext2, ext3,
or ext4 (from the same doc)
* For OWL-R FULL, the second rule (the one on
owl:InverseFunctionalProperty) in Table2, can ?y be a literal?
* OWL-R FULL does allow the following, right?
T(:GreenEagle, rdf:type, :EndangeredSpecifies)
T(:GreenEagle, rdf:type, owl:Class)
T(:GreenEagle, rdfs:subClassOf, :Eagle)
* OWL-R FULL, owl:sameAs rules in Table 1 can be applied to classes,
properties, right?
* The fifth rule in Table 1, can p' be a blank node or literal? I assume
the answer is no. So we may want to add a
general restriction on all rules so that illegal triples cannot be
generated.
* An editorial suggestion. Can we name/number all those rules so that
they can easily be referenced?
That is all for now,
Cheers,
Zhe
Boris Motik wrote:
> Dear Zhe, Jim, Jeremy, Michael,
>
> The recent discussion on fragments prompted Bernardo and me to come up
> with a new version of the fragments document [1] that
> includes a "rule fragment" (which we have called "OWL-R" pending
> someone thinking of a better name). As you can see, the description
> of this fragment (finally!) includes a set of rules that axiomatizes
> OWL Prime as we discussed.
>
> We would be very interested if you have any comments about it before
> we circulate it to the Working Group (which we would like to do
> ASAP).
>
> Regards,
>
> Bernardo & Boris
>
> [1] http://www.w3.org/2007/OWL/wiki/Fragments_Proposal
>
>